Tissue adhesives based on fibrinogen are employed for seamless and/or seam-supporting binding of human or animal tissue or organ parts, for wound sealing, hemostasis and promoting wound healing. Their mode of action is based on the fact that the (soluble) fibrinogen contained in a ready-to-use, liquid tissue adhesive is converted by thrombin into (insoluble) fibrin. Factor XIII may also be included in the liquid tissue adhesive, where it is activated to Factor XIIIa, by the action of thrombin. This crosslinks the formed fibrin to form a high MW polymer which may improve the effectiveness of the tissue adhesive. The required thrombin activity can either originate from the tissue (the wound surface) to be adhered or can be added in the form of a thrombin and Ca2+ ion-containing solution to the tissue adhesive in the course of the sealing. Tissue adhesives based on fibrinogen are known from AT-B-359 653, AT-B-359 652 and AT-B-369 990. Aside from fibrinogen and Factor XIII they may also contain further proteins such as fibronectin and albumin and optionally antibiotic agents. U.S. Pat. No. 5,962,405 (Seelich; Immuno AG) discloses storage-stable fibrinogen preparations in lyophilized form or a form resulting from deep-freezing liquid preparations (deep-frozen) which can be reconstituted and liquefied quickly and in a simple manner to form ready-to-use fibrinogen and/or tissue adhesive solutions. Such preparations are marketed as TISSEEL® fibrin sealant by Baxter Healthcare Corporation (CA, USA).
Hemostatic patches, such as those made from collagen, may be used for sealing tissue and controlling bleeding in a variety of surgical procedures. They can be used with a coating of tissue adhesive, such as fibrin glue. Alternatively, hemostatic patches made from a collagen sponge coated with thrombin and fibrinogen are available, such as TACHOCOMB® hemostatic patches or TACHOSIL® hemostatic patches (Nycomed).
Fibrin sealants and hemostatic patches permit safe hemostasis, good adherence of the seal to the wound and/or tissue areas, high strength of the adhesions and/or wound sealings, complete resorbability of the adhesive in the course of the wound healing process, and may have wound healing promoting properties. Nevertheless, it is usually necessary to hold sealed tissue parts in the desired position for several minutes to ensure that the setting fibrin sealant adheres firmly to the surrounding tissue. Compounds improving the fibrin clot formation and/or strengthening the fibrin clot structure could improve fibrin sealants and hemostatic patches. For example, a strengthened clot would be less prone to fibrinolysis and would be more stable and longer lasting.
The listing or discussion of a prior-published document in this specification should not be taken as an acknowledgement that the document is part of the state of the art or is common general knowledge.